Ignition system



Dec. 8, 1953 B. H. SHORT J'IGNITION SYSTEM Filed Sept. '7, 1951 Patented Dec. 8, 1953 Brooks'H. Short, Anderson, lndig as'signor to General Motors Corporation, Detroit, Micl1.,.a corporation of Delaware Application September 7, 19 511. seen No. 245,497

1 Claims (Cl. ems-214) This invention relates to ignition apparatus for internal combustion engines and its object is to increase the heat of spark by increasing the duration of sparking by means of an auxiliary condenser which is charged between firing intervals and which is provided with a discharge path which occurs at a spark plug when a sparking voltage is induced in the secondary winding of an ignition coil.

In the disclosed embodiment of the present invention, this object is accomplished by the use of a source of high voltage D. C. current which has an output terminal connectable by a periodic engine driven circuit closer with the primary winding of a high frequency ignition coil whose secondary winding is connected by a distributor with the engine spark plugs. This output terminal is connected also through a resistance with one end of the secondary winding and with an auxiliary condenser which is charged between sparking intervals and which discharges across the gap of a spark plug which sparkin is initiated by the discharge of high voltage induced in the secondary winding following interruption of the circuit of the primary winding.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

The figure of the drawing is a Wiring diagram of the invention.

Referring to the drawing, a low voltage D. C. source, such as a storage battery I0, is connected by an ignition switch I with a vibrator 2 which includes a reed l3 connected at one end with a reed support M which provides a low voltage input terminal and carrying a contact [5 for engaging alternately side contacts l6 and I1 and carryin an armature I8 normally off-set from the core IQ of an electro-magnet coil connected with contact I! and terminal |4. Contacts l6 and I1 are connected with the ends of a primary coil 2| of a transformer T, the center tap of coil 2| being grounded. The secondary 22 of transformer T is connected with wires 23 and 30. Wire 23 is connected with plate 24 of cold cathode tube 25 and with cathode 36 of cold cathode tube 35. Cathode 26 of tube 25 is connected with output terminal 40 and with a condenser 3| connected by wire 30 with a grounded condenser 32. Plate 34 of tube 35 is grounded. Wire 30 is connected by resistance 31 with the teasers 38 of the tube 25 and 35, the function of each teaser being to ionize the path between the plate and cathode of its tube. The elements |4--4|l provide a power-pack which receives low voltage direct current from a source It) and impresses high voltage D. C. on the terminal 40.

Terminal 4% is connected by a wire 4| with alternate segments 42 of a periodic current closer 45 having alternate segments 43 connected with the primary coil 5| of a high frequency ignition coil 5|]. An engine-driven shaft 44s drives a rotor 44a carrying a pair of contacts 46 connected by a resistor 41 and carrying a pair of contacts 43 connected by a condenser 49.

The secondary coil 52 of coil 50 is connected with the center contact 53 of a distributor 55 having posts 54 connected with engine spark plugs 56. Shaft 44s drives a rotor 51 carrying a conductor 58 connected with center contact 53 and operating to distribute sparking impulses to the spark plugs 56.

The rotors 57 and 4411 are rotated counterclockwise. The pair of contacts 46 are the leading contacts with respect to the segments 42 and 43 which they connect. While contacts 46 are in engagement with segments 42 and 43, current increases in coil 5|. When contacts 46 separate from the segments 42 and 43, contacts 48 remain in engagement with segments 42 and 43 so that condenser 49 is operative in conjunction with primary coil 5| to obtain a rapid reduction of primary current and coil flux to obtain a high voltage induced in the secondary coil 52 sufficient to cause sparking at a spark plug. The circuit of condenser 49 includes ground, primary coil 5|, condenser 49, wire 4|, terminal 40, and power supply.

During the interval between sparking impulses an auxiliary condenser Cl was charged by the power pack. When sparking occurs at a spark plug, a path for discharge of condenser CI is provided. The discharge of condenser CI prolongs the duration of sparking at the spark plug and substantially increases the heat of spark whereby adequate ignition can be provided at relatively high engine speeds.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

Ignition apparatus for internal combustion engines comprising a high voltage D. C. source having an output terminal, an ignition coil having primary and secondary windings, spark plugs, a distributor having posts connected respectively with the Spark plugs and having an engine driven rotor, a center contact, a conductor carried by the rotor for distributing sparking impulses to the posts from the center contact, a sparking impulse circuit which includes a spark plug, a post, the conductor, the center contact, the secondary winding of the ignition coil, a resistor in series with the output terminal, a primary circuit connected in parallel with the output terminal, and circuit including a periodic circuit closer having fixed segments alternate ones of which are connected as a group with the output terminal and alternate ones as a group with the primary winding of the ignition coil and having an engine driven rotor, two circuit connectors carried thereby for bridging, in sequence, between one each of the two groups of segments, the first of the connectors to be effective including a resistance and the last connector to be effective after the first has become inefiective including a condenser, the circuit of the last connector to be effective including ground, the primary winding of the ignition coil, the said condenser, the output terminal, said firstmentioned resistance, an auxiliary condenser and ground, and a discharge circuit of the auxiliary condenser which includes ground, said auxiliary condenser, the secondary winding of the ignition coil, the distributor and a spark plug to ground.

BROOKS H. SHORT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,489,780 Hooven Nov. 29, 1949 2,536,143 Short Jan. 2, 1951 

